work done depends only on the initial and final positions, independent of the path taken

work done depends not only on the initial point and ending point, but also the path taken.

net work done by the force on an object moving around any closed path is zero

is a property of a system as a whole, not just of the object but also depends on external forces

if no nonconservative forces, sum of change in kinetic energy and in the potential energy is zero and E=K + U

The principle of conservation of mechanical energy states that if only conservative forces are doing work, the total mechanical energy of a system neither increases nor decreases in any process. It stays constant-it is conserved